Step 2-2:
Select login
(under Keychains),and All Items
(under Category).
You will see all items that are being saved in your Keychain Access.
These can include your Airport password for your home Wi-Fi network and / or CAC
websites / Identity preferences that you have visited and used your CAC on
previously.

Step 2-3: Click the
column heading titledKind, scroll down to
Identity preference, now Delete any CAC enabled websites that
you are having problems accessing. You can hold your
control key and click your single button [Mac mouse] and select Delete,
or if you have a two button mouse right click and select Delete. Once they are deleted, close keychain and revisit the CAC
website you are having problems accessing.

Example of mail.mil entries to remove. You may see something different
than "mont."

The Mac OS will cache some information about your CAC in
order to read the data faster the next time it's being used on your
computer. Sometimes this cache can cause issues after receiving a new
ID card. Thursby's suggestion is that you remove your card from the
reader if its present, download the utility from the link below, then
run the app for "if you have received a new card or new certs." This
will clear all of the token cache information by running a Terminal
command. Also, there will not be a completion dialog, and at most
you may be prompted to type in your computer password.

Please run
this utility and contact
Thursby if you
continue to have trouble.